Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The evolution of the actin cytoskeleton after trypsinization and recultivation as well as the effect of the PGE2 modulator and that of the secondary messenger, the cyclic AMP upon the same cytoskeletal proteins in human pulmonary fibroblasts (ICP-23) were studied. The substances were administered simultaneously and after one hour of viral adsorption. Using epifluorescence for pointing out filamentous actin the modifications occurring in this cytoskeletal protein when contacting trypsin and the virus and when PGE2 and cAMP are administered in the experimental variants are observed. Actin arrangement is obviously modified by the viral infection but the restrictive effect of PGE2 and cAMP upon virus replication is correlated with modifications occurring in the actin cytoskeleton.
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PMID:Effect of prostaglandin E2 (PGE2) and cyclic adenosine monophosphate (cAMP) upon actin cytoskeleton in human pulmonary fibroblasts (ICP-23) infected by measles virus. 133 10

Immunoblotting with two examples of anti-Dha to the electrophoretically separated components of antigen-positive membranes gave a positive reaction with a component of the same apparent Mr (40,000) as sialoglycoprotein beta (SGP beta, syn: glycoconnectin, glycophorin C). The Dha antigenic determinant was sensitive to trypsin, but resistant to chymotrypsin and Endo F. By immunoblotting, one anti-Dha failed to react with sialidase-treated Dh(a+) cells, whilst the other gave a positive result. In contrast, neither antibody agglutinated sialidase-treated red cells. SGP beta was precipitated from Dh(a+) and Dh(a-) phenotype red cells by monoclonal anti-beta (NBTS/BRIC 10). SGP beta from Dh(a+) but not from Dh(a-) red cells was stained by immunoblotting with anti-Dha. These results assign the Dha antigenic epitope to SGP beta.
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PMID:Immunochemical characterisation of the low-incidence antigen, Dha. 171 1

The cell-surface glycoproteins CD44 and CD58 are involved in cell adhesion reactions. In this paper 12 monoclonal antibodies in CD44 and two in CD58 are described. Competitive binding assays using CD44 antibodies identified three distinct epitope groups. Antibodies in Group 1 and, with one exception (BRIC 214), antibodies in group 2, but not antibodies in Group 3, recognized epitopes that are sensitive to reduction and to trypsin or chymotrypsin treatment of intact erythrocytes, and so these epitopes probably reside on the N-terminal disulphide-bonded domain of CD44. Antibodies in CD44 did not inhibit the binding of CD58 antibodies to erythrocytes or vice versa. Quantitative binding studies using radioiodinated IgG measured 1888-5592 copies of CD44 and 1772-3290 copies of CD58 on normal erythrocytes. Similar measurements with radioiodinated Fab fragments gave values of 6508-10,450 (CD44) and 3457-7622 (CD58). Immunocytochemical studies indicated that CD44 is much more widely expressed in non-haemopoietic tissues than CD58. Comparison with previously described CD44 antibodies suggests that antibodies in our Group 1 encompass Hermes 2 and that those in Group 2 encompass Hermes 1. All the CD44 antibodies gave weakened reactions with Lu(a-b-) erythrocytes of the In(Lu) type by one or more methods. BRIC 214 and antibodies in epitope Group 3 were used to demonstrate that CD44 on these variant cells gives membrane-bound trypsin and chymotrypsin cleavage fragments of similar molecular weight to those obtained with normal erythrocytes.
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PMID:New monoclonal antibodies in CD44 and CD58: their use to quantify CD44 and CD58 on normal human erythrocytes and to compare the distribution of CD44 and CD58 in human tissues. 172 Oct 39

Immunoblotting under non-reducing conditions with purified human anti-Gya and anti-Hy locates both antigens to an erythrocyte membrane glycoprotein of apparent Mr 46,750-57,500. The antigens are destroyed on intact red cells by the enzymes pronase, trypsin and chymotrypsin, and by treatment with reducing agents. Immunoblotting with anti-Gya and anti-Hy to membranes prepared from red cells pre-treated with an Endo F preparation caused a mean reduction in apparent Mr of the glycoprotein by 11 kDa at the leading and trailing edges, when compared with control membranes. These results suggest that the glycoprotein has one or more complex N-glycans that are not completely sensitive to Endo F digestion on intact cells. The majority of Gya/Hy-active molecules are not tightly associated with the red cell membrane skeleton. A gross reduction in reactivity with anti-Gya and anti-Hy by immunoblotting was observed in red cell membranes from patients with paroxysmal nocturnal haemoglobinuria, suggesting a possible membrane linkage via glycosylphosphatidylinositol for the glycoprotein that carries the Gya and Hy antigens. Immunoprecipitation of the glycoprotein by anti-Gya showed that the protein migrates faster under reducing conditions (Mr 45,000-54,000). A putative dimer was also evident in the precipitates. The glycoprotein was demonstrated to be distinct from lymphocyte-function-associated antigen-3 (CD58), the LWab-active glycoprotein, the Fya-active glycoprotein, the Oka-active glycoprotein and the BRIC 125 glycoprotein (CD47).
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PMID:Evidence that the human blood group antigens Gya and Hy are carried on a novel glycosylphosphatidylinositol-linked erythrocyte membrane glycoprotein. 182 22

The number of Lub antigen sites on the human erythrocyte membrane, as recognised by the murine monoclonal antibody BRIC-108, has been determined. The number of antibody molecules bound per cell on one example of cells of the phenotype Lu(a-b-) with recessive inheritance was an average of around 200 in replicate determinations, which probably represents non-specific antibody binding. A similar number of antibody molecules to this bound to trypsin- or pronase-treated normal cells or cells of the Lu(a-b-) phenotype associated with the inheritance of the X-borne gene, XS2. The number of binding sites on three examples of cells of the phenotype Lu(a-b-) with dominant inheritance was from 440 to 690. A variation in the number of binding sites per cell from 1,640 to 4,070 was found in five individuals with the phenotype Lu(a-b+) and from 850 to 1,820 in four individuals with the phenotype Lu(a+b+). Four individuals with the Lu(a+b-) phenotype had an average of 480 binding sites per cell. The Lub antigen therefore appears to a have low-site density and a variable level of expression on the erythrocyte surface.
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PMID:Estimation of the number of binding sites for a murine monoclonal anti-Lub on human erythrocytes. 366 Jul 70

The CD47 glycoprotein was isolated from human erythrocytes by immunoprecipitation using monoclonal antibody (mAb) BRIC-125. Enzymic deglycosylation of the protein showed it contained N-linked oligosaccharides, and trypsin proteolysis of the protein in situ in the erythrocyte membrane cleaved it into two portions, one of which was glycosylated. Both the intact protein and the glycosylated fragment had blocked N-termini. Amino acid sequence was obtained from several proteolytic fragments of CD47. Comparison with the sequence database showed the protein to be very similar to or identical with OA3, a multispanning membrane protein. The protein also appears to be the same as the integrin-associated protein, which has a role in cell adhesion in non-erythroid cells. CD47 has six potential N-glycosylation sites, five of which are in an Ig superfamily domain. We show that three of these sites carry N-glycans in erythrocytes. Immunocytochemical staining of human tissues showed that CD47 was broadly distributed on mesenchyme and epithelia at multiple sites. Reactivity was particularly prominent in surface and ductular epithelia, and in the brain. The possible roles of the CD47 glycoprotein are discussed.
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PMID:Isolation and characterization of CD47 glycoprotein: a multispanning membrane protein which is the same as integrin-associated protein (IAP) and the ovarian tumour marker OA3. 799 89

The recent genetic discoveries in CP support the hypothesis that inappropriate intrapancreatic activation of zymogens by trypsin results in autodigestion and pancreatitis. Two different protective mechanisms prevent activation of the pancreatic digestive enzyme cascade. First, SPINK1 inhibits up to 20% of potential trypsin activity and, second, trypsin itself activates trypsin-like enzymes readily degrading trypsinogen and other zymogens. Pancreatitis may therefore be the result of an imbalance between proteases and their inhibitors within the pancreatic parenchyma. The discovery of PRSS1 mutations in families with CP was the first breakthrough in the understanding of the underlying genetic mechanisms. Enhanced trypsinogen activation may be the common initiating step in pancreatitis caused by these mutations. The discovery of SPINK1 mutations underlines the importance of the protease inhibitor system in the pathogenesis of CP. Thus, gain-of-function in the cationic trypsinogen resulting in an enhanced autoactivation, or loss-of-function mutations in SPINK1 leading to decreased inhibitory capacity, may similarly disturb the delicate intrapancreatic balance of proteases and their inhibitors. The recent findings of SPINK1, CFTR, and PRSS1 mutations in CP patients without a family history have challenged the concept of idiopathic CP as a non-genetic disorder and the differentiation between HP and ICP. There is a clear mode of autosomal dominant inheritance for some mutations (R122H, N291, possibly MIT), whereas the inheritance pattern (autosomal recessive, complex, or modifying) of other mutations (A16V, N34S) is controverted or unknown. The lack of mutations in the above-mentioned genes in many patients suggests that CP may also be caused by genetic alterations in yet unidentified genes. Evaluation of CP patients without an obvious predisposing factor, e.g. alcohol abuse, should include genetic testing even in the absence of a family history of pancreatitis. Finally, identification of further disease-causing genes will create a better understanding of pathogenesis and may help to develop specific preventive and therapeutic strategies.
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PMID:Genetic aspects of chronic pancreatitis: insights into aetiopathogenesis and clinical implications. 1177 91

Cysteine peptidase inhibitor genes (ICP) of the chagasin family have been identified in protozoan (Leishmania mexicana and Trypanosoma brucei) and bacterial (Pseudomonas aeruginosa) pathogens. The encoded proteins have low sequence identities with each other and no significant identity with cystatins or other known cysteine peptidase inhibitors. Recombinant forms of each ICP inhibit protozoan and mammalian clan CA, family C1 cysteine peptidases but do not inhibit the clan CD cysteine peptidase caspase 3, the serine peptidase trypsin or the aspartic peptidases pepsin and thrombin. The functional homology between ICPs implies a common evolutionary origin for these bacterial and protozoal proteins.
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PMID:Functional conservation of a natural cysteine peptidase inhibitor in protozoan and bacterial pathogens. 1272 89

In this study, selenium species from Se containing proteins in mushrooms (Agaricus bisporus and Lentinula edodes) were investigated with size-exclusion liquid chromatography coupled to UV and inductively coupled plasma mass spectrometry (ICP-MS). Different protein extraction protocols were investigated. Variability of the fractionation patterns with three extraction media (0.1M NaOH, 30 mM Tris-HCl, and enzymatic digestions) was evaluated for both mushroom types. A 24 h Tris-HCl extraction followed by acetone addition was found to be optimal for protein precipitation. Presumably protein bound selenoamino acids were released using enzymes (proteinase K, protease XIV and trypsin). The selenium speciation of the proteolytic extract of the water soluble proteins fraction was carried out by using reversed-phase ion-pairing high performance liquid chromatography (RP-HPIPC) coupled on-line to ICP-MS for selenium specific detection. Selenocystine, selenomethionine, methylselenocysteine and inorganic selenium were established in both samples utilizing retention time standards and standard additions to the sample.
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PMID:Selenium speciation in Agaricus bisporus and Lentinula edodes mushroom proteins using multi-dimensional chromatography coupled to inductively coupled plasma mass spectrometry. 1623

A method based on ICP collision-cell MS detection in capillary HPLC was developed to gain an insight into the purity and identity of selenium-containing proteins separated by 1-D and 2-D electrophoresis. The bands and spots obtained after the separation of water-soluble proteins in selenized yeast were digested with trypsin prior to chromatography. Selenium could be detected down to the subpicogram level. The method, assisted by information obtained by MALDI TOF MS on the 5000 Da cut-off fraction, permitted the purity of bands and spots to be estimated and the efficiency of tryptic digestion and the quantity of selenium present in individual peptides to be evaluated. Owing to the high sensitivity and the lack of matrix suppression effects, the method provided chromatograms with signal-to-noise ratios of 10-1000 in conditions where the common ES Q-TOF MS detection failed.
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PMID:Capillary HPLC-ICP MS mapping of selenocompounds in spots obtained from the 2-D gel electrophoresis of the water-soluble protein fraction of selenized yeast. 1679 77


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